1. Field of the Invention
The present invention relates to apparatus for use in detecting micro-organisms in samples of substances such as foods, beverages pharmaceuticals or pathological samples, such as blood.
2. Description of the Prior Art
Electrochemical methods for detecting the growth of micro-organisms in such samples have been proposed and include measuring conductance, impedance or potential difference changes in the samples. Apparatus suitable for carrying out one such method has been described and claimed in our co-pending U.K. Patent Application No. 8602980. That apparatus comprises a plurality of containers for holding the microbiological samples to be tested and a container-mounting rack into which the containers are inserted for tests to be carried out on the samples.
The apparatus suffers a disadvantage that the sample containers are not particularly stable, either when they are free-standing out of the rack or when received by the rack. This is because of the relatively tall, yet narrow socket member secured to the container which acts both as a base on which to stand the container upright when it is not loaded into the rack and as a means of releasable connection between the container and the rack when the container is received thereby.
A further disadvantage of this known apparatus is that, whilst the apparatus provides means for catching any inadvertent spillage of sample material into the rack by providing a spillage-containment vessel at each station where a sample container is to be located in the rack, there are no means for detecting whether any such spillage into a vessel has occurred. Thus, it would be possible for a container subsequently loaded at that particular station to become contaminated.